1. Human Population: Growth, Demography and Carrying Capacity
AP Environmental Science

2. Human Population Growth Historically
Early Hunter Gatherers
Nomadic, With a Strong Sense of the Earth
Practiced Intentional Birth Control
Rise of Agriculture
Necessary for Survival
Animals became extinct via predation and altered habitat
Humans began to cultivate own food

3. C. Agriculture Gives Rise to Cities
Food Produced in Country, Consumed in City
Food wastes are no longer returned to soil
Soil becomes less productive
Waste of Populations Concentrated in Cities
Population Control in Medieval Societies
Infanticide
Plagues

4. D. Industrialization
View of Children During Early Phases of Industrial Growth
Valued as cheap source of income and cheap labor
Exponential growth of populations
By 1900s, Birth Rate in Industrialized World Dropped
Rise in standards of living
Safe and inexpensive means of birth control introduced
Increase in the cost of child rearing

6. MI L I O NS

7. Population Projections
Over 95% of this increase
will take place in “Developing
Countries”

9. Current World Population
Population Clock Vital Events (per time unit)
Global population was 6,805,057,197
US population was 308,759,035 On February 25, 2010 at 9:05 pam
The global population grows by:
Nearly 2.4 persons per seconds
Nearly 8,868 persons per hour
Over 212,828 persons per day
Over 77,895,029 persons per year

10. How Much is a Billion? 1,000 seconds = 16.7 minutes
1 million-s = 16,677 min = 11.6 days
1 billion-s = 11,574 days = 31.7 years
1,000 pennies = ~ 88 ounces = 5.5 pounds
1 million pennies = 5,500 pounds (~1-Suburban)
1 billion pennies = 2,750 tons (~2 Space Shuttles)

11. Human Population Dynamics
There are just three sources of change in population size —
fertility
mortality
"natural decrease" refers to population decline resulting from more deaths than births
migration
Net migration is the number of immigrants minus emigrants

12. Rates of Global Pop. Change use: International Data Base http://www
Rates of Global Pop. Change use: International Data Base then Online Demographic Aggregation
CBR (crude birth rate) = # births / 1000 population
1990: 24 now: 20.6
CDR (crude death rate) = # deaths / 1000 population
1990: 9 now: 8.8
Growth Rate = (b + i) – (d + e)
1990: 1.5% now: 1.15%
Growth rates have come down
Doubling time = 70/1.15 = 61 years

15. Human Population Dynamics
Total fertility rate (TFR)
The average number of children born to a woman
Average in developed countries = 1.5
Average in developing countries = 3.8
Worldwide 1990: 3.1 now: 2.76
Replacement fertility rate (RFR)
The number of children a couple must have to replace themselves
A TFR of 2.1 for developed countries with low infant and child mortality rates
Africa RFR = 2.5

17. What Is Family Planning?
Definition
Measures enabling parents to control number of children (if they so desire)
Goals of Family Planning
Not to limit births
For couples to have healthy children
For couples to be able to care for their children
For couples to have the number of children that they want

19. China’s Program
Nation With Best Known Population Control Program
Reasons Chinese Government Initiated Population Control Measures
Freshwater and food at a premium for nation’s population
Country experiencing population momentum
Government Perks / Coercive Measures for Citizen Compliance
Free education and health care
Increased personal and family incomes
Increased legal marrying age for women
Contraceptives, abortions, and sterilizations free of charge
Preferential housing and retirement income

20. What Methods are Used to Control Births?
Preconception Birth Control Methods
Barrier Methods
Condom
Vaginal sponge
Diaphragm
Spermicides
Hormonal Contraceptives
Pill
Injections and implants
Sterilization
Postconception Birth Control Measures
Intrauterine Device
RU-486 Pill
Abortion

21. Contraceptive Use Worldwide
People in industrialized countries enjoy easy access to contraceptives while those in LDCs do not.
In the U.S., teens and poor women are least likely to use contraceptives.
Severe problems are associated with teen pregnancy.
Teens don’t receive the care they need.
More adolescent girls die from pregnancy-related causes than any other cause.
Maternal mortality is twice as high for women younger than 20, and 4 times as high for women younger than 17.
Each year about 15 million young women ages have babies.
Survival rate for babies born to teens is low.
Young age of mother can cause problems with the child.
Teen pregnancy causes greater public expenditures.

22. Human Population Dynamics
infant mortality rate
IMR
infant deaths per 1000 live births (infant < 1 yr)
1990: 62 now: 52.4 (normal in 1900: 200)

23. http://www. povertymap

24. www.tte-online.com/.../table-of-contents/ chem-enc-1.html

25. Maternal Deaths per 100,000 Live Births
Source: WHO, UNICEF, UNFPA Maternal Mortality in 1995: Estimates Developed by WHO, UNICEF AND UNFPA, 2001.

26. Migration
Net migration is the number of immigrants minus emigrants

28. Overall, the world population is growing at a rate of about 1
Overall, the world population is growing at a rate of about 1.7% (2002); if this rate continues, the population will double in 42 years.
Unabated, such a rate would lead to a point about 2000 years hence when the mass of humanity would weigh more, and be larger, than the Earth.
But, the growth rate is decreasing

30. Population Pyramids Graphic device: bar graph
shows the age and gender composition of a region
horizontal axis: gender
male: left-hand female: right-hand
absolute number of people or %
vertical axis: age
5-year or 10-year age groups

31. Population Pyramid with young cohorts

32. Population Pyramids Moderate Growth: Mexico Zero Growth: U.S.
High Growth: Afghanistan
Moderate Growth: Mexico
Zero Growth: U.S.
Negative Growth: Austria or Italy

33. Demographic Transition
Movement of a nation from high population growth to low population as it develops economically
Transition as a result of four stages
Stage 1—Birth and death rates are both high
Stage 2—Death rates fall; birth rates remain high; growth rate rises
Stage 3—Birth rates fall as standard of living rises; growth rate falls
Stage 4—Growth rate continues to fall to zero or to a negative rate

37. The Demographic Transition
                                                                                                                                                                

38. Five Stages of the Demographic Transition
Used to be 4, now 5 stages
birth rates, death rates and growth rates systematically change through time as societies change:
modernize, urbanize
gain access to technology

39. Stage 1
high birth rates, high (at time erratic) death rates, low growth rates
stage for much of human history, traditional societies
practically no country today

40. Stage 2 high birth rates, declining death rates, rising growth rates
improvements in
sanitation (water)
and medicine
in Europe during Industrial Revolution
in developing countries since the 50s/60s
much of Africa today, some countries of Asia (Afghanistan, Nepal, etc.)

41. Stage 3 continued decline of death rates, declining birth rates,
growth rates decline from
high to lower levels
change in behavior: adaptation to lower death rate, in particular infant mortality rate
economic change: urbanization (incentive to have fewer children)
Mexico today

42. Stage 4 & 5 Stage 4: low birth rates, low death rates, low
growth rates
United States today
Stage 5: low birth rates, rising death rates, declining growth rates (if birth rates drop below death rates: negative growth rates)
several countries of Europe today (Austria)

43. Population Pyramids and Demographic Stages
characteristics shapes of ‘pyramids’
wide base (true pyramid)
wide middle (bulge), somewhat wider base
urn- or bottle-shaped
reversed pyramid
different shapes--different dynamics

44. Population Pyramid and Demographic Transition
Stage 2: wide base
stage 3: wide middle
stage 4: slender
stage 5: narrow base

45. Population Pyramid and Demographic Transition
Stage 2: wide base
stage 3: wide middle
stage 4: slender
stage 5: narrow base

46. Population Pyramid and Demographic Transition
Stage 2: wide base
stage 3: wide middle
stage 4: slender
stage 5: narrow base

47. Population Pyramid and Demographic Transition
Stage 2: wide base
stage 3: wide middle
stage 4: slender
stage 5: narrow base

48. Demographic Trap
Population Path of Most Less-Developed Countries (LDCs)
“Trapped” in Stage 2 of Demographic Transition
Before 1970, LDCs seemed poised to make transition thanks to economic growth
Since 1970, economic growth has not kept pace with population
High birth and low death rates result in explosive population growth
Downward spiral in standard of living

49. Demographic Fatigue
Condition characterized by a lack of financial resources and an inability to deal effectively with threats such as natural catastrophes and disease
Possibility that countries suffering from demographic fatigues could slip back into Stage 1 of demographic transition

50. Age Structure & Population Projections
Baby boomers - half of U.S. population; use most of goods and services; make political and economic decision
baby-bust generation - born since 1965; may have to pay more income, health care and social security to support retired baby boomers; but face less job competition
Better health may --> later retirement of baby boomers --> keep high-salary jobs

51. Tracking the baby-boom generation in the United States

52. Effects of Population Decline
As percentage of 60+ aged people increases, population begins decline
60+population increase --> severe economic and social problems because 60+ consume
more medical care
Social Security
costly public services
Labor shortages require automation & immigration

54. The Graying of Japan
Family-planning access, cramped housing, expensive land, late marriage, education cost --> voluntary decrease in birth rate
Low immigration rate
Health insurance and pension - 45% of national income; could -->low economy
Illegal immigration bolsters work force

56. Influencing Population Size
Most countries restrict immigration
Canada, Australia, U.S. - most immigration
Involuntary immigration results from
armed conflict
environmental degradation
natural disaster --> environmental refugees
~1% of developing nations pop. Emigrates
Migration from rural to urban areas

58. Family Planning: reduce births and abortions
59% contraceptive use in developed countries -46% overall, up from 10% in 60s
FP reduces children's social services needs
FP reduces risk of childbearing deaths
FP effectiveness depends on program design and funding:
good in some counties with good program
poor in other counties

59. Family Planning: reduce births and abortions -2
Services not always accessible; add female teenagers and sexually active unmarried
Add birth control for men (sperm-killing device used in China)
If developed countries provided $17 billion/ year, and each person pays $4.80/year, average family size would be 2.1 and world population would be 2.9 billion

60. Rewards and Penalties to reduce births
What might work:
encourage, rather than coerce, people to have fewer children
reinforce existing customs and trends toward smaller families
don’t penalize for already existing larger family
increase poor family’s economic status

61. Empowering women to reduce births
Women tend to have fewer, and healthier children when:
they have access to education and paying jobs outside home
their society doesn’t suppress women’s rights
But women do most of the work
not shown in GDP because of lower pay
Women excluded from economic and political decision making

62. Case Studies - India
Family planning efforts began in 1952; fertility rate declined from 5.3 to 3.4 but population growth is still exponential -1.9%
Disappointing results due to:
poor planning
bureaucratic inefficiency
low status of women
extreme poverty
lack of administrative & financial support

63. Case Studies - China
Family planning efforts began in 1970; TFR fell from 5.7 to 1.8; infant mortality and illiteracy rates 1/3 to 1/2 of India’s rates
Population control program is extensive, intrusive and strict:
postpone childbearing
only one child/family -->benefits
effect b/c China is dictatorship; limited resources would have mean disaster

64. Cutting Global Population Growth
U. N.Conference on Population and Development, Cairo, 1994
8 goals to be met by 2015 (p. 276)
are these goals wishful thinking?
Replacement level fertility can be met in years as shown by Japan, Thailand…
Invest in family planning, reduce poverty, and elevate status of women

65. Short of thermonuclear war itself, rampant population growth is the gravest issue the world faces over the decades immediately ahead. If we do not act, the problem will be solved by famine, riots, insurrection and war.
Robert S. McNamara